[Ovirt-devel] Explicit global network modelling

[Mohammed Morsi]

Daniel P. Berrange wrote:
> The network configuration UI discussions have all focused around
> the idea of configuring NICs on machines. I've been thinking that
> this is really not the right model. You have some kind of physical
> topology which is known, and has certain properties like network
> address and prefix, and vlan.  A host has one or more NICs, each
> of which is connected to a network.
>
> So if we can model a network as a global entity in its own right,
> we can simplify configuration of host interfaces, so simply a 
> matter of association, and optionally defining an address.
>
>
> * Network
>     - addr config      eg, none, static vs dhcp
>     - network address  eg, 192.168.122.0
>     - prefix           eg,  /24
>     - usage            eg, storage, management, guest
>     - vlan number      eg, 43
>     - vlan network     eg, name of host network
>
> * Interface
>     - name              eg eth1
>     - mac               eg 00:11:22:33:44:55
>     - addr config       eg, static vs dhcp vs none
>
> With the association being:
>
>            1     n           n    1
>   Network  <-----> Interface <----> Node
>
>
>   
Based on our discussion today the following things are needed for this


1. Add new networks table, subclassed into virtual and physical
networks, and associated with ip_addresses table
2. Unassociate nics and bondings with ip addresses, associate with networks
3. Change any backend components that depend on the model changes
4. Add tab to dashboard if user is able to edit default pool for
networks, allowing user to view, create, edit, delete networks. Should
come with FIXME to change permissions to something more robust, either
by subclassing Network table from Pool (breaking necessary bits into any
additional tables) or the most rebust way, to refactoring the permission
model to accommodate permissions assigned to any object
5. Update nics / bonding interface to associate w/ a network as opposed
to an ip address.


I can take care of the interface bits (eg 4,5) if Darryl or someone else
takes care of the first three.


One additional thing that comes to mind as I read over the proposed
changes is that this network model fits nicely with DHCP assigned nics /
interfaces as the nic is associated with the network which it is to
receive that information from, but for static assignments it doesn't fit
so nicely. This is because the nic / interface will still need to be
associated with an ip address directly and not just a network. If so
we'd still need the associations between those tables, and might require
some validation to make sure the assigned ip is valid for the selected
network (or would no network be selected in that case?).

   -Mo